PMC_ATTACH(3) BSD Library Functions Manual PMC_ATTACH(3)NAME
pmc_attach, pmc_detach — attaching and detaching process scope PMCs to
target processes
LIBRARY
Performance Counters Library (libpmc, -lpmc)
SYNOPSIS
#include <pmc.h>
int
pmc_attach(pmc_id_t pmcid, pid_t pid);
int
pmc_detach(pmc_id_t pmcid, pid_t pid);
DESCRIPTION
These functions control the set of target processes tracked by a process
scope PMC.
Function pmc_attach() is used to attach a process scope PMC specified by
argument pmcid to a target process specified by argument pid. Argument
pid may be zero to denote the current process. If the PMC was allocated
with modifier PMC_F_DESCENDANTS, the PMC will additionally attach to cur‐
rent and future descendents of the specified target process. The PMC
should be in a quiescent state (i.e., not running).
Function pmc_detach() is used to detach a process scope PMC specified by
argument pmcid from a process specified by argument pid. Argument pid
may be zero to denote the current process.
RETURN VALUES
Upon successful completion, the value 0 is returned; otherwise the
value -1 is returned and the global variable errno is set to indicate the
error.
ERRORS
A call to function pmc_attach() may fail with the following errors:
[EBUSY] Argument pmcid specified a PMC that was not in a qui‐
escent state.
[EBUSY] The target process specified by function pmc_attach is
being tracked by another process scope PMC that uses
the same PMC hardware resources.
[EEXIST] The target process is already being tracked by the
specified PMC.
[EINVAL] Argument pmcid specified a PMC with system scope.
[EINVAL] Argument pid specified an illegal process id.
[EINVAL] The current process does not own a PMC with the handle
specified in argument pmcid.
[EPERM] The caller lacked the privilege needed to attach PMCs
to the specified target process.
[EPERM] (i386 and amd64 architectures) The PMC specified by
argument pmcid has been setup to allow the use of the
RDPMC instruction for self measurement.
[ESRCH] The current process does not own any PMCs.
[ESRCH] The process specified by argument pid did not exist.
A call to function pmc_detach() may fail with the following errors:
[EINVAL] Argument pmcid specified a PMC with system scope.
[EINVAL] Argument pid specified an illegal process id.
[EINVAL] The current process does not own a PMC with the handle
specified in argument pmcid.
[EINVAL] The specified PMC was not attached to the target
process.
[ESRCH] The current process does not own any PMCs.
[ESRCH] The process specified by argument pid is not being
monitored by hwpmc(4).
[ESRCH] The process specified by argument pid did not exist.
SEE ALSOpmc(3), pmc_start(3), pmc_stop(3), hwpmc(4)BSD November 25 2007 BSD
